This section describes commands
that are useful in network troubleshooting.
Probably the most common is the PING command which sends an echo test message to
another machine. If we get an echo we know that everything from the Network
layer down is OK.

Network
layer and down are OK

Network layer and
down are not OK

Echo requestèçEcho
reply

Echo requestèEcho requestèEcho requestè

Use PING [computerName] to do a normal echo
test. Use PING -a [IPaddress] to determine a computer's name or DNS name.